Speaking at the start of a U.N. Human Rights Council session, Zeid Ra'ad al-Hussein denounced how "another brutal security operation is underway in Rakhine state — this time, apparently on a far greater scale."

Zeid, a Jordanian prince, noted that the U.N. refugee agency has reported that 270,000 people have fled to neighboring Bangladesh in the last three weeks, and pointed to satellite imagery and reports of "security forces and local militia burning Rohingya villages" and extrajudicial killings.

He said Monday that he was "further appalled" by reports of Myanmar authorities planting land mines along the border.

"The Myanmar government should stop pretending that the Rohingya are setting fire to their own homes and laying waste to their own villages," he added, calling it a "complete denial of reality" that hurts the standing of a country that recently enjoyed "immense good will."